Tall, self supporting, hardy perennials

[WellTidy]

I am trying to give my borders some interest by adding a bit of height. I've bought lots of salvias, which I adore. So I am looking for things that are similar really. I am a novice, so want easy things that are as long flowering as possible, ideally don't need staking, are hardy (as I am on a budget) and are only white, pink or purple. So far my ideas are silene, delphinium and agapanthus which tick some but not all boxes!

I will be planting nerine bowdenii, lupin and allium bulbs for next year, but wondered what I could buy for this year.

Not really a gardener, but having read your subject line I now totally aspire to be a tall, self-supporting, hardy perennial!

Penstemons, Iris, Thalictrum.

You'll probably need to stake delphiniums. Another vote here for iris they are lovely. A peony?

Do foxgloves count? Hollyhocks?

Japanese anemone (good for shade), veronica

If you don't want to stake, look at native plants which have to hold their own such as the already mentioned foxgloves, eupatorium, agrimony, oenothera, columbine, campanula, angelica, epilobium, lythrum, centranthus, valerian, and so on.

Eupatorium, especially Riesenschirm (spelling?)
Filipendula rubra venusta
Persicaria polymorpha
Persicaria orientalis (annual)
Verbena bonariensis
Cosmos Purity (annual)
Crambe cordifolia

.... will all exceed 3-4 ft

Verbena

Cephalaria gigantea, giant yellow scabious. 6ft and no staking required. Bees love it. They also love white globe thistle, Echinops sphaerocephalus.

Verbena bonariensis
Hollyhocks
Foxglove
Sweet rocket is tall, scented and while not perennial, sets seed to regrow reliably and attractive to wildlife. Needs support though.
Delphiniums are floppy. As are lupins sometimes (and they're just snailbait in my garden!)

Sadly tall usually means support but you can do it subtly

Oh yes, globe thistle can be good. Can need support. Depends on how windy it is and where!

do you know about the Chelsea Chop?

In the last week of May (when the Chelsea flower show is on), you can cut back many perennials by 1/3 of their height and they will regrow more sturdily and with longer flowering season. NB this does not apply to plants which flower early nor to those which have their flowers on long stems or spires(eg geums, hollyhocks, salvia).

It is good for sedums, phlox, penstemon if you get them early enough, and many others. Info here

Thank you all very much for fantastic advice. I don't have any of anything that has been suggested, except verbena, so I have lots to choose from! And now that I know about the Chelsea chop, I can buy the plants that can be chopped as I don't have any if them either!

Campanulas. The tall ones. May need a little staking, but self set like mad. Good value for money and earn their keep.

I walked past our local market today and stopped at the plants stall. I bought pink salvia, tall white and purple campanula, foxglove Dalmatian rose, pink and blue Veronica and penstemon. Lots of plants, all for £35. Such a bargain, compared to my local garden centre. I have a list of others to buy but I have made a start!

And pink scabiosa.

Aconitum, russian sage

Cardoon or artichoke. Lovely architectural plants, don't need staking, add height to a border and you can even eat the artichoke!

Steve

I can almost hear Bob Flowerdew.

I'd also like some of these for my garden.